Hi Eric, I will let you know how it goes with the Mp1 antenna 
which I hope to get Thursday.  It might work for you.  Far as the 
Kenwood 480, I have used mine on low power say 25 watts which is 
not the lowest power as you know, and have still managed to work 
a station in Colorado on 20 meters on a crappy random wire 
literally tossed into a tree, and more recently have worked some 
60 meter stations on my Windom which has a very bad match on that 
band but even so, I work stations using 25 or 30 watts with no 
problems.
Am excited to try the Mp1 outside using a 12 volt battery and 
probably reduced power to make the battery last.  Good luck, Jim 
WA6EKS